1. Technical Field
The disclosure relates in general to a method for manufacturing a semiconductor device, and more particularly to the method for manufacturing a semiconductor device having undamaged gates in different regions.
2. Description of the Related Art
In the conventional method for manufacturing the devices on a substrate, part of the devices would be fully covered by the protection layer when other devices are fabricated. For example, the NMOS device is fully covered while the PMOS device is constructed, such as forming the recesses for epitaxially growing the SeGe layer. However, the unprotected gate of the PMOS device may be damaged during fabrication process. In the conventional method, lithography for forming recesses removes portion of the gate in the PMOS region while the gate in the NMOS region is fully protected. Due to the different protection conditions of the devices, the gate heights of the devices are different and the subsequent process would cause damage to the gates (ex: in the PMOS region). The damaged gates have considerable effect on the performance characteristics of the devices.